Just posted at AVS.
Thanks to ckna and mr. smith2.50 firmware
For further info you may want to pop in at AVS and read pages 9-^
This file is a .nrg cd iso, the zip file is about 9MB.AVS Link to 2.50 info

I have one of the first RP-91's. It has the original firmware setting (cant remember number). Will updating to the newest firmware also include the 236 changes or do I need to install the updates individually and in order?

I had an orignal as well, I went to the 2.36 update and it didn't seem to do much. It MAY have moved the picture slightly to the left (solving the shift right problem). But that's about it. I would really like to know the benefits of the 2.50 updates before I burn another CD and try it.

Well, I changed my mind and upgraded it. Doesn't seem to do much. The picture is still shifted to the right.
Anyways, for the Mac OS X.1 users, I've created a .dmg (inside a .sit file) of the CD.
I have hosted the disc image here, temporarily.
(I say temporarily because I don't want a bazillion downloads of this 12.6 MB file off the server I'm using. Perhaps someone else can host the file?)
To burn the disc under Mac OS X.1:
First click on the "PanasonicRP91_250.sit" file to unstuff the .dmg file. Then launch Disk Copy. Go to the Disk Copy menu bar and select Image --> Burn Image. It will ask you where the image is located. Select the "PanasonicRP91_250.dmg" image file to burn it.
(Note that you cannot burn the image if it is already mounted. If OS X has automatically mounted it, then make sure you drag the mounted drive to the trash first.)
I know it works because what I did was burn the disc from the .nrg file using Nero under Win XP, then make a .dmg file from OS X Disk Copy, and then reburn a second disc. I used the second disc to update my RP91.
N.B. Although I know the file works, I take no responsibility for anything that may go wrong at your end.

Pretty much Arthur. It will come up with a screen that says that the upgrade is needed and ask if you want to continue. Use your remote to select "yes" and it takes care of the rest. Mine took about five minutes, the player then "rebooted" itself, and then came up with a screen saying that the upgrade was complete. I then turned the player off, then back on, and checked the firmware version to see that it was right, then played a few dvd's to make sure all was well.